I'd say that between the AFM and hall sensor, it's hard to call one more
important than the other. You need both for the engine to work in a useful
manner. Sure, it'll idle with the AFM disconnected, but that's all. The
Digifant ECU needs what pretty much any FI controller needs. Not sure what
there is to discuss about it. It pretty much just sprays in the appropriate
amount of fuel (as determined by the AFM) at the right time (as determined
by the hall sensor). There are other sensors (temp, O2) that tweak the mix
a little, but it's not really that much different (with the exception the
obvious mechanical vs. electronic control) than the old Bosch dual-point
fuel injection first fielded in the bf109 in 1938.

John Bange
'90 Vanagon "Geldsauger"

>Does anyone know how Digifant works?  I think
>that the hall sender input to the ECU is more
>"important" than the AFM input.  That is, if
>you unplug the hall sender when the engine is
>running, you'd get NO injection pulse.  But
>if you unplug the AFM, you'd get a small injection
>pulse anyway.
>
>Anyone agree/disagree?  Thoughts?